The clock rate of a processor can vary dynamically while a computing device is powered on, which allows the processor to conserve power. For example, the clock rate can vary from −50% to +20% from a baseline or nominal clock rate in response to workload characteristics and/or measurements from the processor's physical environment. The variation in clock rate is typically performed asynchronously such that an operating system or hypervisor is not aware that the clock rate has changed. The efficient and accurate assessment of the clock rate, however, is fundamental to interpreting performance metrics that are associated with the processor and one or more workload partitions on a computing system.